30
"
 Suppose you are typing a very long command line:
 PATH='/home/alw/bin:/home/alw/bin:/home/alw/bin:
 /usr/local/sbin:/usr/local/bin:/usr/sbin:
 /usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 /snap/bin'
 You discover a mistake before you hit Enter. Or
 you discover it later and call the line back in
 your history. You can edit on the command line,
 of course, but if you prefer your editor of
 choice press Control+X Control+E. Your default
 editor (usually set with $EDITOR or $VISUAL)
 will start with the command loaded.
 https://bit.ly/2Y96wc4
 "